An information delivery system delivers information from the source (where it's produced) to the target (where it's consumed). Sometimes timing is so crucial that information must be delivered in a timely manner (or in real-time). On the other hand, such a system must make sure that information will not reach the targets where it's not requested. Conclusively, an ideal information delivery system must guarantee the accuracy, completeness, and timeliness of information delivery.
However, it has become increasingly difficult to reach these goals in an era in which the reliance on information has become more and more prominent and a tremendous amount of information has been accumulated. On one hand, people are thirty for information, increasingly depending on information and information-related technologies in their daily lives. Businesses also operate around information, and business owners and leaders rely heavily on information to make business decisions. In the mean time, information is accumulated at a pace that storage devices can hardly catch up with. As a result, people are overwhelmed and sometimes annoyed by the huge amount of information they receive, including unsolicited information such as electronic spam or junk mails. Ironically, people have difficulty obtaining the right information actually because they receive too much information.
Information is power, but only when it reaches the people who request it. More often than not, published information doesn't reach all the wanting targets when it is generated. For example, an advertisement from a store may never reach a customer looking to purchase a particular product, although the promotional price is in the range the customer wants to pay. Since the desired information delivery is not achieved, people have to retrieve the missed information later on among a huge amount of information, possibly resorting to a search engine.
As another problem of information delivery, information that reaches a wrong target bears no value and thus becomes annoying junk. For example, people who do not own a home frequently get annoyed by information they receive about home loan refinancing because the information is of no value to them.
The third problem associated with information delivery is that information is often not delivered in real-time or timely. Consequently, information whose value is strongly tied to a timely delivery loses its value if it's not delivered to the right targets in time. For example, information about a flat TV sale on Sunday doesn't help a TV buyer if the information is received on the following Tuesday.
These information delivery problems occur because the model of the current information delivery is usually either pull-based or push-based.
With a push-based delivery model, information producers push information to all possible targets in order to reach the maximum number of correct targets. For example, a grocery store sends out promotional advertisements by mail to all the people in the neighborhood, in spite of the fact that some of the people may never visit this store. As a result, information producers waste resources while information consumers that are wrong targeted get annoyed. Underwood, et al. in “User-Centered Push for Timely Information Delivery” describes such a push-based information delivery method. Ishikawa, et al. describes another technology in implementing a push-based information delivery.
With a pull-based information delivery model, however, information consumers pull information from information sources, usually by browsing or searching for the information. For example, people usually visit certain websites to get certain type of information. If they don't know which website contains the information they need, they usually use a search engine to help find web pages that might contain the needed information. Browsing and searching are often required even if the visitors know exactly which website has the information they need.
A search engine helps a consumer retrieve the information from anywhere on the Web, but at the same time it also pulls in a massive amount of seemingly related information. In reality, a search engine doesn't always return the right result. Nor does it do so without burying the requested information in a large amount of intruding information.
With either a push-based or pull-based model, there is a disconnection between the information producers and consumers and a lack of an agreement about what information should be delivered to the consumers and when it should be delivered. Because of the disconnection and the lack of the agreement, information is often delivered not to where it's mostly needed, but to where it's not needed at all. Moreover, because of the disconnection between the information producers and consumers, it is very difficult to achieve timeliness of information delivery.
A publish-subscribe model is also used for information delivery. Traditionally, newspapers and magazines are published and delivered to subscribers using such a model. Nowadays, a visitor of some websites may subscribe to, mostly, newsletters or alerts published by the owner of the site, by making a few selections and providing an email address. For instance, https://diss.state.de.us/DWS/public.diss provides a service that allows a user to subscribe to information updates provided by Delaware agencies and government entities via emails.
In the information era, publish-subscribe models are predominantly used in proprietary Enterprise Application Integration (EAI) systems, where the applications within an enterprise computer system communicate with each other by exchanging messages or events. Each message or event is published by an upstream application and matched and delivered to the corresponding downstream applications that show interest in that type of messages or events.
While a publish-subscribe based information delivery model such as those used in EAI systems has certain advantages over either push-based or pull-based models and can potentially achieve accuracy, completeness, and timeliness of information delivery, it helps little in solving the current information delivery problems due to its limitations.
First of all, EAI systems are proprietary and inoperative with each other. As a result, information publication, subscription, and delivery are restricted to one vendor or one system and have failed to scale up to larger, more generalized networks such as a large Intranet or the Internet.
Secondly, the information exchanged in an EAI system must confirm to a predefined, machine-readable format that's mutually understandable by both upstream and downstream applications. Therefore, such a system is not suitable for delivering general, free-formatted information such as news, events, articles, and personal announcement for human consumption. For instance, XML document is suitable for computer to consume but a human reader more likely prefers the same information in plain text or PDF format.
Finally, an EAI system failed to provide an efficient cataloging mechanism storing and managing information such as who are publishing and what are published, and it doesn't permit flexibility in information publication, subscription, and delivery, which is desirable for human-consumed information.
In summary, neither push-based nor pull-based information delivery fulfills the accuracy, completeness, and timeliness of information delivery. Publish-subscribe based information delivery is successful only in proprietary EAI systems and is not suitable for delivering general information on a large scale for a large audience. What's needed to completely address the information delivery problems is an method and system that achieves accuracy, completeness, and timeliness of information delivery, scales up to be suitable for delivering information on an Intranet or the Internet, delivers general information suitable for human consumption, provides a centralized information publication catalog to facilitate information publication and subscription, provides a common marketplace where information can be published, subscribed to, and delivered among a large audience of information publishers and subscribers, and allows flexibility in information publication, subscription, and delivery. The invention is such a method and system to address the current information delivery problems.